I know that many of you watched the first two episodes of EARTH A New Wild last week on Public Television, including Episode 2: Plains. I watched as well, and while I was glad for the attention paid to grasslands, I also had some concerns about the content of the Plains episode. If you didn’t see it, you can watch it here.
The recent measles outbreaks in the United States have been the topic of much discussion lately. While there is a great deal of finger pointing going on regarding vaccinations, I worry that a bigger issue is being ignored; in today’s noisy world, it is very difficult for the public to know what information is based on good science and what is not. The growth of the anti-vaccination movement is a good showcase of the issue, but the problem is much broader, spanning topics from climate change to dietary supplements. It often seems that anyone with charisma and/or a loud voice can gain credibility and a following, especially if they are promoting a message that feeds people’s fears or tells them what they want to hear. Cutthroat politics and a desire among media outlets for provocative stories both stoke the fire, and there is almost no way for the average citizen to sort truth from propaganda.
As a scientist who spends a lot of time and effort communicating about science, this is something I really struggle with. I try really hard to present only the best information I can, and to distinguish between facts, assumptions, and opinions. At the same time, I do have an agenda – I want to see prairies conserved, and I feel strongly that factors such as biodiversity, habitat heterogeneity, and ecological resilience are critically important. While there is a lot of research that backs up those assumptions, I still have to acknowledge my biases, and I try to be careful not to pass off opinions as science. It’s very difficult.
All of this is leads back to my main topic of this post; my disappointment in the Plains episode of EARTH A New Wild that aired on Public Television last week. I was disappointed with the program because I thought it presented a very one-sided perspective on some ideas, and their promoter, Allan Savory, that are very complex and widely disputed. To be fair, the narrator of the series, M. Sanjayan, did mention that Savory and some of his theories are controversial, but not that numerous scientists and studies have actually contradicted those theories. Instead, he appeared to endorse Savory’s ideas, and much of the episode explored how they could be applied in grasslands around the world. I welcome any attention paid to prairie conservation issues, but I felt the Plains episode led people to believe that the strategies it advocated were better supported by science than they really are.
My intent with this blog post is not to discredit or disprove the theories and ideas promoted by Savory or the Plains episode. Instead, I want to provide additional information that I hope will help round out some of the topics presented in the episode and facilitate a productive discussion among those who watched it. The following are a few pieces of information I feel are important to be aware of as you consider the potential value and application of the ideas presented in last week’s show.
Controversy over Savory’s Big Ideas
- Allan Savory gave a TED (Technology, Entertainment, Design) talk back in 2013 that gained a lot of attention because of its assertion that “planned grazing” was necessary to reverse desertification and climate change. In fact, he claimed that his method of intensive, concentrated grazing is the only viable solution to reverse those two processes. The most specific rebuttal (among many) to that talk was published by five eminent grassland scientists in a Society for Range Management journal (Rangelands 35(5):72-74. 2013). The rebuttal addresses each of the main claims made in the TED talk and refutes them. Unfortunately, the article is not available online to those who don’t have a subscription allowing access to SRM publications. A brief summary and links to some responses to the rebuttal are included at the end of this post if you’re interested.
- There were many other critiques and rebuttals of Savory’s TED talk, including one by George Monbiot in The Guardian and another by James E. McWilliams in Slate. Both echo many of the points made in the Rangelands rebuttal, and also provide links to other information, including numerous scientific studies that refute both Savory’s TED talk claims and the broader success of his Holistic Management grazing practices. You can read a rebuttal to Monbiot on the website of the Savory Institute.
- To be fair, it’s important to separate Savory’s “bolder” theories about desertification and climate change from his more moderate Holistic Management and planned grazing ideas, which have been incorporated by a segment of the ranching community across the world. Among other things, Holistic Management encourages careful planning and monitoring, which is certainly positive, but its proponents also tend to promote the use of higher stocking rates than many rangeland scientists feel are sustainable. The results of scientific studies evaluating the results of Holistic Management and planned grazing have been decidely mixed. Some studies have supported Savory’s theories, but many others showed that planned grazing either didn’t deliver the promised benefits or performed less well than other grazing systems. As is typical in the scientific process, more data needs to be collected and research projects need to be repeated to resolve the inconsistent findings so far. In the meantime, however, it seems premature to conclude that Savory’s grazing strategies are obviously and significantly better than other options.
- Allan Savory is vocal about his distaste for the use of fire for managing grasslands and excludes it from his land management recommendations. Coincidentally, there was no mention of fire in the entire Plains episode, despite it being one of the three major forces that control grassland ecosystems (along with grazing and drought). An example of Savory’s thoughts on fire can be found in a quote from An Overview of Holistic Management and Holistic Decision Making from the Savory Institute’s website, which says that fire “pollutes the atmosphere and exposes soil contributing to desertification/climate change.” Climate change and its contributing factors comprise a very complex web, and I sure can’t say that fire is not part of that web, but it’s also important to consider the way fire affects carbon in the atmosphere, a topic I covered in an earlier blog post. Of course, fire can have both negative and positive consequences, as can any management tool, depending upon the way it is applied. However, most people working in prairie conservation feel that prescribed fire is a very important tool, and there is abundant research that supports that view. One synthesis of that research can be found here, and Chapter 4 (page 29) deals with central North America, in particular.
The Complex Issue of Prairie Dogs
- During the segment on prairie dogs and black-footed ferrets, the Plains episode highlighted the ability of prairie dogs to increase the health of grasslands. They create habitat for other species by burrowing, and grazing/clipping of vegetation by prairie dogs can increase the forage quality of grassland areas. All of that is true and important. However, research also shows that prairie dogs can change the composition of a plant community in ways that lower forage quality and/or quantity available for livestock and other animals. As a result, there is strong evidence that prairie dogs can compete with livestock for forage.
- I was disappointed that the Plains episode focused only on the positive aspects of prairie dogs, especially because it also talked about (and showed) ranchers working to eradicate prairie dogs without really explaining why. Balancing the ecological benefits of prairie dogs with the economic impacts they can have to ranchers is a key component of prairie conservation in North America. It is a complex and multi-faceted issue that requires understanding and empathy on all sides if it is going to be resolved. Here are links to two recent research publications that highlight the complexities of the prairie dog issue. The first is publicly accessible, but the second is only available to those who have journal access subscriptions. Thank you to my friend Stephen Winter for providing these citations.
Both Savory and Sanjayan are charismatic speakers, and very effective salesmen. The ideas presented in the Plains episode of EARTH A New Wild are attractive because they appeal to our romantic sense of balance in nature, and imply that we can play an important role in re-setting that balance. I agree that large predators are key components of ecosystems, and that we should find ways to live with them when it’s possible, and attempt to replicate their role when it’s not. However, I felt the Plains episode unnecessarily focused on a very narrow set of theories and proposals for grassland conservation; a set built upon widely and vigorously challenged assumptions. I am very optimistic about our ability to conserve our grasslands and other ecosystems, but doing so will require robust and well-rounded conversations and a wide range of strategies. As we continue those conversations, it will be imperative that we are upfront with each other about which strategic options are based on good science and which are not.
Here are the main points from the rebuttal to Savory’s TED talk that was published in the journal Rangelands. The rebuttal essentially focuses on Savory’s presentation piece by piece, including:
1) Pointing out the fallacy of Savory’s statements that all non-forested lands are degraded and that rangeland science fails to either understand the reasons for or to be able to mitigate that degradation;
2) Laying out the physical impossibilities of Savory’s claim that changing the way grasslands are managed could solve climate change;
3) Pointing out that photos were the primary evidence used to support Savory’s claims of restoring degraded grasslands and that several of the photos he used either had a different grazing history than Savory claimed or were from a completely different location than Savory stated.
4) Refuting Savory’s statements about the benefits of hoof action breaking up biological crusts in desert grasslands to increase water infiltration by pointing to the well-studied ecological roles (protecting soil from wind erosion and carbon loss) played by those same crusts.
For those of you who do have access to the Rangelands journal, I hope you will read not only this rebuttal article, but also a response from Richard Teague and the subsequent response to that critique. In addition to providing context around Savory’s climate change and desertification theories, the series of three short articles also provides an excellent synopsis of the many arguments among scientists trying to understand the complexities of grazing management.